The BTR-3U is fitted with the one-person KBA-105 "Shkval" unified fighting module which can accommodate 30mm gun, 7.62mm coaxial machine gun, 30mm automatic grenade launcher and anti-tank guided weapons. This module was developed by the State Scientific Technical Centre of Artillery & Rifle Arms of Ukraine. The Shkval fighting module design is very flexible, which makes it possible to easily replace an existing weapon with another one.
The 30 mm dual-feed cannon has 350 rounds of ready-use ammunition.
A total of 2,500 rounds are carried for the 7.62mm coaxial machine gun.
The 30 mm grenade launcher is mounted on the left side of the turret, having 29 rounds of ready-use ammunition, with additional 87 rounds being carried in reserve (three magazines, each containing 29 rounds).
Six 81 mm electrically operated smoke/aerosol grenade launchers are mounted three either side of the turret rear and firing forwards.
The sighting systems include a commander’s 1PZ-3 observation periscope and a TKN-4S Agat stabilised sight which is integrated with the missile fire control system.
The standard equipment of the BTR-3U also includes hydraulically amplified powered steering on the front four road wheels and a central tire-pressure regulation system that allows the driver to adjust the tire-pressure to suit the terrain being crossed. The BTR-3U is fitted with French Michelin tires.
The BTR-3U engine compartment consists of a Deutz BF6M1015 diesel developing 326 hp coupled to an Allison MD3066 fully automatic transmission. The power pack and transmission are fitted by the Kharkiv Morozov Machine Building Design Bureau with the technical assistance of the Deutz AG and the Allison Transmission companies. The engine compartment is fitted with an automatic double-action fire extinguishing system.
The vehicle is fully amphibious, propelled when afloat by a single water jet mounted at the rear of the hull. To prepare the vehicle for water, the driver erects a trim vane and switches on the bilge pumps from within the vehicle.
The troop compartment accommodates six soldiers who enter and leave the vehicle by a door in either side of the hull. The lower part of the door folds downward to form a step, with the upper part opening forwards. There are also hatches in the roof and firing ports with associated vision devices provided in the sides and front of the vehicle. An air conditioning system is fitted as standard to ensure crew comfort in hot conditions.
- BTR-3U "Okhotnik": initially known as BTR-94K. As described.
Guardian: version for UAE Marines with "Buran-N1" turret.
- BTR-3E: probably with UTD-20 engine.
- BTR-3E1: latest version with BM-3 "Shturm" turret and new engine.
- BTR-3E ARV: recovery vehicle with winch, crane and dozer blade.
- BTR-3E 90: heavy fire support vehicle with 90mm Cockerill main gun.