The invention relates to a catalytic reactor with a compact construction, whose assembly prevents the biomaterial present in said reactor from fusing together and causing a malfunction. The two cooperating pieces, when interlocked, approximate a long shaft, generally tubular in cross-section, with a recessed area on the male piece adapted to receive the annular restoration hub. The device feature can be formed on the beveled portion as with a pair of spaced, adjacent barrier material lines that are substantially void of residual shorting stringers extending therebetween. The drilling template is capable of assuming at least one configuration when the at least two layers are prevented from moving with respect to each other.