I don’t believe so, I just know LBs can’t be buried underground.
I think so but you would be able to remove or fish new wire through it
National Electrical Manfacturing Association
I have mine outside, under an eave and it’s been fine with the exception of some UV discoloration.
Wall thickness is just over 1/8". if pipe ID is 1/2 that gives 3/4 OD (grey pvc) plus this LB so 1/2 + 1/8 x 4 equals just over 1"
if used with pvc glue at the ends, do not deform cover when applying, light silicone caulk at seal is best.