Lexan one piece design. Waterproof, air trapping, submersible design works like inverted water glass. Exceeds Federal #108 requirements for sing and combined functions. Bulb slides for readily accessible bulb servicing. 180� visibility legal side marker/clearance light. Combine with reflectors. 1/4" stud mount. 5-1/2"L x 7/8"W x 1-1/2"H.